[問題]大全987-188

[Alycia]

188. By installing special electric pumps, farmers’ houses could be heated by the warmth from cows’ milk, according to one agricultural engineer.
(A) farmers’ houses could be heated by the warmth from cows’ milk, according to one agricultural engineer
(B) the warmth from cows’ milk could be used by farmers to heat their houses, according to one agricultural engineer
(C) one agricultural engineer reports that farmers could use the warmth from cows’ milk to heat their houses
(D) farmers, according to one agricultural engineer, could use the warmth from cows’ milk to heat their houses
(E) one agricultural engineer reports that farmers’ houses could be heated by the warmth from cows’ milk

The answer is D....I chose C...."By +Ving..." should be followed by a subject, right? so...I thought "one agricultural engineer" is the subject in this case?

[Pufa]

C:
One agricultural engineer reports something by installing special electric pumps?

有點無厘頭 ，錯囉。